#!/usr/bin/env python3
#
# Copyright 2023 The Dawn & Tint Authors
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice, this
#    list of conditions and the following disclaimer.
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# 2. Redistributions in binary form must reproduce the above copyright notice,
#    this list of conditions and the following disclaimer in the documentation
#    and/or other materials provided with the distribution.
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# 3. Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
"""Script for updating the active milestones for the Dawn project.

This is largely based on the Chromium equivalent in
chromium/src/infra/config/scripts/milestones.py.

To activate a new branch, run the following from the root of the repo (where MMM
is the milestone number and BBBB is the branch number):
```
infra/config/scripts/milestones.py activate --milestone MMM --branch BBBB
infra/config/global/main.star
```

To deactivate a branch, run the following from the root of the repo (where MMM
is the milestone number):
```
infra/config/scripts/milestones.py deactivate --milestone MMM
infra/config/global/main.star
```
"""

import argparse
import json
import os

INFRA_CONFIG_GLOBAL_DIR = os.path.realpath(
    os.path.join(os.path.dirname(__file__), '..', 'global'))


def parse_args():
    parser = argparse.ArgumentParser(
        description='Update the active milestones for the Dawn project')
    parser.set_defaults(func=None)
    parser.add_argument('--milestones-json',
                        default=os.path.join(INFRA_CONFIG_GLOBAL_DIR,
                                             'milestones.json'),
                        help='Path to the milestones.json file to modify')

    subparsers = parser.add_subparsers()

    activate_parser = subparsers.add_parser(
        'activate', help='Add an additional active milestone.')
    activate_parser.set_defaults(func=cmd_activate)
    activate_parser.add_argument(
        '--milestone',
        required=True,
        type=int,
        help='The milestone identifier/release channel number')
    activate_parser.add_argument(
        '--branch',
        required=True,
        help='The branch name, which should correspond to a ref in refs/heads')

    deactivate_parser = subparsers.add_parser(
        'deactivate', help='Remove an active milestone')
    deactivate_parser.set_defaults(func=cmd_deactivate)
    deactivate_parser.add_argument(
        '--milestone',
        required=True,
        type=int,
        help='The milestone identifier/release channel number')

    args = parser.parse_args()
    if not args.func:
        parser.error('No sub-command specified')
    return args


def _sort_milestones(milestones):
    # We have to manually sort here instead of relying on
    # json.dump(..., sort_keys=True) later since we only want to sort the top
    # level keys, not all keys.
    milestones = {
        str(k): milestones[str(k)]
        for k in sorted([int(s) for s in milestones])
    }
    return milestones


def add_milestone(milestones, milestone_num, branch):
    if str(milestone_num) in milestones:
        raise RuntimeError('Milestone %d already exists' % milestone_num)

    milestones[str(milestone_num)] = {
        'name': f'm{milestone_num}',
        'chromium_project': f'chromium-m{milestone_num}',
        'ref': f'refs/heads/{branch}',
        'platforms': [
            'linux',
            'mac',
            'win',
        ],
    }

    return _sort_milestones(milestones)


def remove_milestone(milestones, milestone_num):
    if str(milestone_num) not in milestones:
        raise RuntimeError('Milestone %d does not exist' % milestone_num)
    del milestones[str(milestone_num)]
    # Not strictly necessary, but returning a value keeps this consistent with
    # add_milestone.
    return milestones


def cmd_activate(args):
    with open(args.milestones_json) as infile:
        milestones = json.load(infile)
    milestones = add_milestone(milestones, args.milestone, args.branch)
    with open(args.milestones_json, 'w') as outfile:
        json.dump(milestones, outfile, indent=4)


def cmd_deactivate(args):
    with open(args.milestones_json) as infile:
        milestones = json.load(infile)
    milestones = remove_milestone(milestones, args.milestone)
    with open(args.milestones_json, 'w') as outfile:
        json.dump(milestones, outfile, indent=4)


def main():
    args = parse_args()
    args.func(args)


if __name__ == '__main__':
    main()